HALIFAX—A Canadian researcher who co-led a study that challenges well-worn advice to limit meat consumption has responded to criticisms he should have disclosed past ties to the global meat and food industry.
Dalhousie University’s Bradley Johnston says he followed the disclosure rules of the Annals of Internal Medicine, which published the work Sept. 30. Those rules required the report’s panel of 14 researchers from seven countries to reveal outside funding received within three years.
The Halifax professor and epidemiologist said the last time he received money from the International Life Sciences Institute, an industry trade group, was almost five years ago, and that he has cut all ties since.
“We seek to be totally independent of industry and in fact we are,” Johnston said in an interview the day after the New York Times delved into his background.
“Three years is a standard used by the ICJME (International Committee of Medical Journal Editors) and many guideline groups, and my declaration was accurate, and there is no undisclosed conflict.”
However, a professor of nutrition and food studies at New York University said that while Johnston followed the letter of the disclosure rule, he “ignored its spirit.”
Marion Nestle said the report’s methodologies and conclusions on red meat are similar to Johnston’s industry-funded work on sugar consumption, which also deemed the evidence to cut intake as weak. The Annals of Internal Medicine published that study in December 2016.
“It is always better to err on the side of more disclosure, not less,” Nestle wrote in an email.
“This one would ordinarily be in a grey area, but because the sugar study was so similar in approach, analysis, and conclusions, it would have been better to disclose.
Nestle, the author of “Unsavory Truth: How Food Companies Skew the Science of What We Eat,” said that while the International Life Sciences Institute lists itself as an independent think tank, “it is supported by a large number of food and beverage companies. More important, it represents food-industry interests in the United States and internationally.”
The institute lists its members and supporting companies in 2015 as including McDonald’s, Coca-Cola, and Cargill, one of the largest beef processors in North America.
Nestle said the journal editor should add further background to the disclosure information already published in the Annals of Internal Medicine.
The panel of scientists in the red meat study concluded evidence that links the food to cancer, heart disease, and other bad health outcomes is weak. They wrote that if there is a health benefit to giving up meat products, it’s small.
The journal article was examining previously reported data that a reduction of three red meat servings per week offered seven fewer cancer deaths per 1,000 people.
The authors found that evidence linking red meat consumption to cancer, heart disease, and other bad health outcomes is weak, and if there is a benefit to giving up meat products, it’s small.
Gordon Guyatt, a celebrated professor and researcher at Hamilton’s McMaster University who supervised a team of global researchers for the study, says that given the increased risks are slight and uncertain, cutting back wouldn’t be worth it for people who really enjoy meat.
Guyatt says he knew the series of papers he and his colleagues published would elicit blowback, but he did not expect anything like the widespread torrent of condemnation that continues to stream forth, among them letters to the editor excoriating the methodology and a petition by a Washington-based doctors’ group to retract the work because it allegedly “promotes physical harm to those who follow its dangerous advice.”
“It’s completely predictable and they’re doing themselves no favours from my point of view about these sort of hysterical statements about: It shouldn’t be published, let’s keep it out of public view, let’s not have scientific discourse operate as it should operate,” he says.
“It’s hysterical. It’s a hysterical response.”
The team used an evaluative system known as GRADE to assess the evidence provided by previous dietary studies, and looked at how inclined most people actually were to forsake red meat for their health.
Dr. David Jenkins, professor of Nutritional Sciences and Medicine at the University of Toronto, said in an interview that the issue of Johnston’s non-disclosure of past ties is a minor matter.
“The critiques should focus on the work itself,” said Jenkins, who faults the work for failing to consider environmental and animal welfare arguments to reduce meat consumption.
He fears the work could further confuse the general public and other health professionals, taking special issue with the publication’s headline that declared: “New guidelines: No need to reduce red or processed meat consumption for good health.”
He is among a group of scientists known as the Physicians Committee for Responsible Medicine who pressed the Annals of Internal Medicine for a retraction, arguing the conclusions would put some “at risk for major health problems.”
“The evidence against us giving up meat may be weak, but it’s there. And the evidence for us eating more meat is not there,” he said.
The Harvard University school of public health also issued a release this week critical of the study.
The school said there is a large body of evidence indicating consumption of red meat—especially processed red meat—is associated with higher risk of type 2 diabetes, cardiovascular disease, certain types of cancers and premature death.
“Existing recommendations (on food consumption) are based on solid evidence from randomized controlled studies,” said the release.
Guyatt’s analysis doesn’t suggest red meat or processed meats are healthy or that people should eat more of them, but he also doesn’t discount the possibility that people who eat a lot of meat are in good health.
“I’m sure there are millions, tens of millions, hundreds of millions of people who eat a lot of meat who are in good health,” he says.
Still, he says there needs to be greater acceptance that there is a lot of uncertainty in life, and that on some issues, definitive conclusions cannot be drawn.
“They’ve taken a pretty extreme stance and pushed very hard. And that’s been going on for a long time,” he says, referring to those who oppose meat.
“When that is fundamentally challenged, it is very threatening. And when it is challenged by credible academics with compelling evidence on which to challenge it, that intensifies the threat.”
By Michael Tutton